Photog, you really should consider this:
http://www.epdmcoatings.com/rv_roof_repair.html
I used it to repair and completely reseal the old roof on my class A.
Cost about 300 bucks and that was enough to completely redo a 36 foot roof.
This is the same liquid EPDM rubber roof material that the RV manufacturers use.
It can be purchased in rolls, as they do, but it can also be applied like paint.
It rolls out like thick honey, and is self leveling.
The best part is, you cover the whole roof, seams, etc. No more leaks.
It's like a brand new, one piece roof. Took me one half day to do the whole coach (they even used pictures of my coach on their website- it's the one with the barn in the background with a green X) The before and after pics speak for themselves.
I was quoted 7 grand by the dealer to remove the old roof and install a new one.
This process cost me 300 bucks and half a day. You have to clean the roof, let it dry, and then just roll it out like thick paint.
Amazing stuff.
Of course, all this assuming that the roof is structurally sound, and just needs a new EPDM waterproof coating.
Anthony